Island



(1% Model.)

L. F ARNOLD.

FASTENING FOR TENON JOINTS.

No. 559,924. Patented May 12, 1896.

*1, 3. XMAS Jud/ 5 17 A1110 25L.

UNTT ED STATES PATENT OFFICE.

LUCIUS F. ARNOLD, OF PIIENIX, RHODE ISLAND.

FASTENING FOR TENON-JOINTS.

SPECIFICATION forming part of Letters Patent No. 559,924, dated May 12, 1896.

Application filed December '7, 1895. Serial No. 571,439. (No model.)

T 0 alZ whmn it may concern:

Be it known that I, LUCI'US F. ARNOLD, a citizen of the United States, residing at PhelllX, in the county of Kent and State of Rhode Island, have invented certain new and useful Improvements in Fastenings for Tenon- .Ioints and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters of reference marked thereon, which form a part of this specification.

Myinvention relates to fastenin gs fortenonjoints, and more particularly to tenon-joints of furniture, such as chairs,stands, tables,and analogous articles, as well as other kinds of wood-joining; and it consists, essentially, in the combination with a member having a mortise provided with aretaining-shoulder, of an automatically-expansible shouldered tenon member mounted in said mortise and interlocking therewith, all as will be more fully hereinafter set forth and claimed. In tenonjoints as hitherto made (excepting the wellknown glued joint) it has been usual,so far as I am aware, to effect the fastening of the tenon within the mortise by means of a metallic member interposed between and snugly fitting the adjacent surfaces of the mortise and tenon. Such former construction obviously increases the cost of manufacture, since it involves the use of an additional or third member.

The object I have in view is to provide a strong and comparatively inexpensive fastening for tenon-joints, said fastening being effected without the employment of a third or intermediary member.

iy means of my improvement tenon-joints can be put together with greater facility, the fastening being stronger and forming a positive locking device, thereby preventing the tenon member from withdrawal or even becoming loose.

In the accompanying sheet of drawings, Figure 1 is asoctional view of a mortise member, showing a mortise-hole embodying one part of my present improvement. Fig. 2 is a side view of my improved tenon. member. Fig. 3 is an end viewof it. Fig. at shows the parts combined as in use. Fig. 5 is an enlarged sectional view of the mortise, showing a slightly-modified form of the retainingshoulder. Fig. 6 shows the mortise combined with a cylindrical-shaped tenon, and Figs. '7, 8, 0, and 10 show my improvement as adapted to various forms of dowel-pins and forming blind joints.

IVhile my improvement is more especially applicable to the tenon-joints of furniture, it is also well adapted to other kinds of woodjoinin I would further add that in putting the parts together, when they embody my improved fastening device, I prefer to make the joints without glue, the parts being dry, although in some cases the use of glue or other suitable adhering material may be deemed advisable.

Again referring to the drawings, Z) indicates, say, a chair-leg or standard or mortise member, the same being provided with a socket or mortise I), and forming a seat for the tenon, soon to be described. The form of the mortise may be conical or tapering, as shown in Figs. 1, i, 5, &c., or even straight with parallel sides, as in Figs. 6 and 8. The inner end of the mortise is enlarged transversely to form a groove, as at 6 thereby producing a circular projection or step'c, which I term a retaining-shoulder. This latter may be formed at right angles with the axis of the mortise, or it may be slightly inclined, or hooking, as shown enlarged at 0 Fig. 5.

a indicates a stretcher or chair-rung or other tenon-carrying member, which is to be firmly fastened to said mortise member I). The end portions of the member a are practically the counterpart of the mortise and form the tenons proper, as a. The outer or free end part of the tenon is enlarged, thereby forming a circular rib or projection 0, whose dimensions are substantially the same as the groove 6 of the mortise, said rib being so constructed that it is adapted to spring into engagement and interlock with the said retaining-shoulder 0. Now, since it is evidently impossible to insert the ribbed tenon into the mortise intactthat is, if the two be practically alike in size-I subject the tenon after it has been turned or shaped to a saw or other suitable tool which operates to slit it, as at s. The arrangement of these slits may be substantially as represented in Fig. 3, wherein they extend across the tenon at right angles to each other, thus dividing it into four tongue-like portions, all integral with the tenon. Obviously the slits may be differently arranged; but in any event the enlarged end portion of the tenon must be capable of springing into the groove Z1 after it has been forced past the retaining-shoulder of the mortise.

In Figs. 7 to 10, inclusive, I have shown my improvement applied to modified forms of dowel-pins. In thus joining two boards or pieces of wood together to form a close or blind joint the adjacent faces or edges are first trued and prepared, after which the grooved mortises b b are formed therein, the mortises of one part being in alinement with those of the other part. The pins or tenon members a, cut to the proper length, are next placed in one series of mortises and driven home, after which the other part is placed in position, the mortises thereof also being in position with respect to the projecting portion of the said pins, followed by forcing it ahead until the edges of the two parts are in snug contact, at which instant the pins will have become seated by springing into the corresponding grooves of the mortises. Thus it will be apparent that the retaining-shoulders o of the sockets of the two parts Z) Z) are thereby rigidly interlocked with the corresponding shoulders of the ribbed portion 0 of the several pins or tenons.

My improved fastening for tenon-joints is very strong and is practically non-separable. It is cheaply made and can be easily and quickly put together. trance of the tenon into the mouth of the mortise,-the end of the former may in some cases be rounded, substantially as shown at 0 Fig. 8.

I claim as my invention and desire to secure by United States Letters Patent 1. 111 a mortise-and-tenon joint, the combination with a mortise, having a contracted entrance, and a squared shoulder behind said entrance, of a tenon having its end split so as to be compressible, said end when so compressed being eapable of entering said contracted entrance, and said end being provided with a retaining-shoulder substantially at right angles to the direction of outward pull of the tenon, whereby the pressure of said shoulder against the squared shoulder of the mortise will resist said outward pull without compressing the tenon end, substantially as described.

2. In 'a mortise-and-tenon joint, a tenon having its end split along two planes intersecting in the end, and provided with an aunular flange or shoulder extending outwardly substantially at right angles to the direction of outward pull of the tenon, whereby the pressure of said shoulder against a corresponding shoulder in the mortise will resist said outward pull without compressing the tenon end. I

In testimony whereof I have affixed my signature in presence of two witnesses.

LUCIUS F. ARNOLD.

Witnesses:

Geo. 1L Rnnmo'roN, E. E. HALE.

To facilitate the en-. 

